In the find panel, I would like to assign the history's (up/down) arrows to alt + (up/down).

Then assign the (up/down) keys to dismiss it like currently escape does. This would allow me to drop the incremental search and use the find pannel for everything, thus simplifying the logic of find usage.

Would be possibly interested also in doing the same thing with the (left/right) keys.

There should exist definitions in the Key Bindings file which allowed the customization of these actions.